A liquid level detection device in the related art which detects a liquid level of a liquid stored in a container using a relative angle of a rotating body relative to a fixed body is known. A liquid level detection device disclosed in Patent Literature 1 includes a fixed body fixed to a container, a rotating body rotating relative to the fixed body, a float floating in a liquid, and an arm connecting the rotating body and the float and allowing the rotating body to rotate with up and down motions of the float. The arm is formed by bending a tip end which is to be inserted into the rotating body. The rotating body includes an insertion hole in which the tip end of the arm is inserted in an insertion direction, a holding portion provided with a receiving opening which receives the arm in an intersecting direction intersecting with the insertion direction and holds the received arm, and a hook. The hook includes an L-shaped portion preventing the arm from coming off the receiving opening.